" This course will explore a diverse collection of striking biological phenomena associated with the X chromosome. We will examine the genetic basis and significance of several X-linked mutations. We will also discuss why men are more likely than women to display X-linked traits. We will look at the different mechanisms by which X chromosome gene expression is equalized in mammals, flies, and worms and how these mechanisms can yield unusual phenotypes. Throughout our discussions of the X chromosome we will use both recent and classic primary research papers to learn about this chromosome's fascinating biology. This course is one of many Advanced Undergraduate Seminars offered by the Biology Department at MIT. These seminars are tailored for students with an interest in using primary research literature to discuss and learn about current biological research in a highly interactive setting. Many instructors of the Advanced Undergraduate Seminars are postdoctoral scientists with a strong interest in teaching."